Field of the Invention
The present invention relates to a holder and a vibration generator, particularly to a holder, which is used in a vibration generator that moves a vibrator to generate a vibration by passage of a current through a coil, and the vibration generator.
Description of the Related Art
Various vibration generators having a structure, in which a vibrator including a magnet is supported by a chassis with a spring unit interposed therebetween, are used as the vibration generator that moves the vibrator to generate the vibration. This kind of vibration generator includes a coil, which is disposed below a magnet while being opposite the magnet. When a current is passed through the coil to generate a magnetic field, the vibrator moves while deforming a spring unit.
For example, Document 1 discloses a vibration generator having a structure in which a vibration unit having the magnet is supported using a plate spring. In the vibration generator, one plate-like coil is disposed opposite the magnet of the vibration unit. One end of the plate spring is fixed to a chassis with a screw. The other end of the plate spring is fixed to a weight of the vibration unit by caulking.
Document 2 discloses a vibration generating device, in which the magnet is attached to a movable block and the coil is wound around a rod-shaped yoke body disposed along the magnet. In the vibration generating device, the spring unit supporting the movable block and a frame are integrally molded using a resin material.    [Document 1] Japanese Patent Laying-Open No. 2003-24871    [Document 2] Japanese Patent Laying-Open No. 2010-94567
In the vibration generator disclosed in Document 1, the vibrator is supported using the plate spring attached to the chassis. Therefore, a structure of a portion in which the plate spring is attached onto the chassis side becomes complicated. Specifically, in the vibration generator disclosed in Document 1, the plate spring is attached to the chassis with the screw. Therefore, an assembly man-hour of the vibration generator increases, and the number of components also increases, which increases a production cost of the vibration generator.
The problem becomes more prominent with increasing demand for downsizing and a low profile of the vibration generator. That is, because the downsizing of the component advances with the downsizing of the vibration generator, it is necessary to adopt attachment methods, such as spot welding, instead of screw clamp or caulking, and the structure of the attachment portion between the components becomes complicated. For example, in the case that the spot welding is performed to the attachment portion of the plate spring and the chassis, it is necessary to perform the spot welding at many points in order to maintain high reliability of the vibration generator, and sometimes it takes a lot of trouble with the production. This is because a region where the spot welding is performed is relatively brittle against an impact force.
The vibration generating device disclosed in Document 2 has the structure in which the spring unit and the frame are integrally molded, and the problem with the method for joining the spring unit and the chassis is not originally generated. However, in this case, unfortunately the material used for the chassis is restricted to a material, which can be molded while being integral with the spring unit.
An object of the present invention is to provide a holder, which is used in the high-impact-resistance, easily constructible, and low-production-cost vibration generator, and the vibration generator.